The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Internal combustion engines combust a fuel and air mixture to produce drive torque. More specifically, air is drawn into the engine through a throttle. The air is mixed with fuel and the air and fuel mixture is compressed within a cylinder using a piston. The air and fuel mixture is combusted within the cylinder to reciprocally drive the piston within the cylinder, which in turn rotationally drives a crankshaft of the engine.
An air filter is often used in an internal combustion engine to remove contamination from the induction air. Over a period of use the air filter can become plugged and restrict the air flow into the engine. This can reduce performance, reduce fuel economy and increase engine emissions. Therefore, it is important to determine whether air flow is restricted as a result of the air filter.
Traditional internal combustion engines include pressure sensors both upstream and downstream of the air filter. Accordingly, a traditional engine system is able to diagnose air flow restriction resulting from an air filter based on a calculated pressure drop across the air filter using the upstream and downstream pressure sensors. However, such additional hardware increases cost and manufacturing time, and is also a maintenance concern because proper operation of the sensors must be monitored and the sensors must be replaced if not functioning properly.